The present invention relates to a mixing chamber for use in connection with a hot blast stove system which furnishes hot blast to a blast furnace.
In such a system, a hot blast stove is first placed in an "On Gas" condition, until it has been sufficiently heated, after which an air blast is passed therethrough which is heated thereby for introduction into the blast furnace. It is highly desirable, for satisfactory operation of the blast furnace, to maintain the blast entering the furnace at a relatively constant temperature.
The cycle of a hot blast stove during which the air is passed therethrough is normally referred to as "On Blast". It is clear that at the beginning of the "On Blast" cycle, the stove is at its maximum heating capacity and as the cycle proceeds, its heating capacity gradually decreases. In order to maintain the temperature of the blast entering into the furnace at the desirable constant temperature, what is normally done is to mix into the hot blast leaving the stove a selectively adjustable amount of cold blast so that the temperature of the resultant blast mixture can be controlled. Thus, at the beginning of the "On Blast" cycle of a stove, when it is the hottest, a greater amount of cold blast is required to be mixed therewith than near the end of the cycle when the blast exiting the hot blast stove is not nearly as hot, in order to maintain the blast mixture at the desired constant temperature.
The mixing of cold blast with the hot blast exiting the stove is usually accomplished in a mixing chamber situated just prior to the entry of the mixture into the blast furnace and an example of a blast stove system in which such mixing chamber is utilized is shown in U.S. Pat. No. 3,034,775 incorporated herein by reference, particular reference being made to FIG. 1 thereof wherein the mixing chamber referred to above is identified by the reference character M.
Since the air blast entering the blast furnace is a mixture of hot and cold blast, it is most desirable that such mixture be thoroughly mixed to produce a homogeneous air blast, constant in temperature throughout its extent. Conversely, it would be most undesirable to have the air blast entering into the blast furnace, comprise of a nonuniform/homogeneous mixture continuously varying in temperature from values above the desired temperature to values below the desirable temperature.
Accordingly, it is important to provide a mixing chamber capable of creating a thoroughly mixed uniform and homogeneous mixture of hot and cold blast. It is therefore an object of the present invention to provide an improved mixing chamber adapted to provide a thorough mixture and blending of the hot and cold blast to provide a homogeneous resulting mixture having a uniform temperature for introduction into the blast furnace.